ISRO is preparing to launch the GSAT-N2 satellite, also known as GSAT-20, using SpaceX's Falcon 9 rocket. This mission, set for the second quarter of 2024, marks ISRO's first commercial launch with SpaceX and is part of a broader initiative to enhance internet connectivity in India, particularly in-flight internet services.

The GSAT-N2 satellite weighs approximately 4,700 kg and is designed to operate in the Ka-band frequency range, providing high-throughput satellite (HTS) capabilities with a throughput of around 48 Gbps. It features 32 user beams—8 narrow spot beams focused on the Northeast region and 24 wide spot beams covering the rest of India.

However, ISRO is unable to launch the GSAT-20 (also known as GSAT-N2) on its own launch vehicle due to the satellite's weight, which is 4,700 kg. This exceeds the maximum payload capacity of ISRO's current heavy-lift rocket, the Launch Vehicle Mark-3 (LVM-3), which can only carry about 4,000 kg to geostationary transfer orbit (GTO).

As a result, ISRO has contracted SpaceX to launch GSAT-20 using its Falcon 9 rocket, which can handle payloads up to 8,300 kg . This decision was also influenced by the unavailability of commercial slots with Arianespace, ISRO's previous partner for heavy satellite launches, as their Ariane-5 rocket has been retired and the successor, Ariane-6, is fully booked for upcoming launches.

Furthermore, geopolitical factors have limited options for ISRO; Russian rockets are currently unavailable due to the ongoing conflict in Ukraine, and China is not a viable partner for India . Thus, SpaceX has become the most reliable option for launching heavier satellites like GSAT-20. The launch is scheduled for November 19, 2024.

ISRO's Failings of Timely Development of A Heavy-Lift Launch Vehicle

ISRO (Indian Space Research Organisation) has faced several challenges in developing a heavy-lift launch vehicle (HLV), which can significantly impact its capabilities in the global space market. ISRO is severely underfunded and as a result the development of space systems suffers to a great extent.

One of the most critical issues is the lack of advanced engine technology. ISRO has not fully mastered semi-cryogenic engines, which are essential for heavy-lift capabilities. The current LVM-3, while classified as a heavy-lift rocket, still falls short of international standards and has less than one-third the payload capacity of comparable rockets like China’s Long March 5. The absence of high-thrust variants and advanced engines has hindered ISRO's ability to compete effectively in launching heavier payloads.

ISRO's historical approach has been somewhat reactive rather than proactive with a slow span of development pace. The organisation traditionally operated on a supply-driven model, launching satellites first and then seeking customers, which has now shifted to a demand-driven model since 2019. This transition has created an oversupply of launch vehicles relative to actual demand, complicating the justification for developing new heavy-lift capabilities. Moreover, the development timeline for new rockets often exceeds ten years, which is considerably long compared to other global players like SpaceX.

The economic considerations plays a significant role in ISRO's strategy. Developing a new heavy-lift vehicle requires substantial investment, and currently, there is insufficient domestic demand for such capabilities. It is often more cost-effective for ISRO to book commercial launches with foreign providers like SpaceX rather than invest in developing its own heavy-lift capabilities that may not see frequent use. This reliance on foreign launch services reflects a gap in domestic payload requirements that could justify the expense of developing an HLV.

ISRO is working on the Next Generation Launch Vehicle (NGLV), also known as Project Soorya, which aims to enhance its heavy-lift capabilities by targeting payloads up to 10 tonnes to Geosynchronous Transfer Orbit (GTO). However, this project is still in its early stages, with significant technological advancements and funding proposals required before it can be realized. The NGLV's first launch is anticipated around 2034-2035, indicating a long wait for enhanced launch capabilities.

ISRO's challenges in developing a heavy-lift launch vehicle stem from limitations in engine technology, historical operational models, economic considerations, and the lengthy development timelines associated with new rocket technologies. While future projects like NGLV aim to address these gaps, the path forward will require overcoming significant technical and market-related hurdles.